The present invention concerns an electric set-point transmitter for automotive vehicles, particularly as gas-pedal system, having an actuating element and a resistance element which is connected to the actuating element, an electric voltage which indicates the position of the actuating element being obtainable at one output of the electric set-point transmitter.
In electric set-point transmitters for automotive vehicles, particularly for gas-pedal systems, extremely high dependability is required. In known set-point transmitters of this type, potentiometers in which a wiper contact wipes over an electric resistance path are used, to be sure, to convert the mechnical position into an electric voltage. However, they have various disadvantages; in particularly, a reliable contact between the wiper contact and the resistance path is not always assured.
There are, to be sure, conductive-plastic potentiometers which are extremely reliable and can be used at the high temperatures which occur in automobiles, especially near the engine. These conductive-plastic potentiometers, however, have the disadvantage that the contact between wiper and resistance path can be subjected only to very small currents.
High-ohmic lines, however, lead to disturbances, particularly in an automotive vehicle. Thus, for instance, leakage paths produced by moisture as well as electrical and magnetic influences are substantially more noticeable than in the case of low-ohmic lines. Furthermore, contacts of plug connections and switches tend more frequently to error when their current load is extremely small.